The present invention relates to methods for performing surgery and instruments used therewith, in particular micro-surgical methods and techniques and the instrumentalities used therewith to determine anatomical structure of the surgical site. The present invention more particularly relates to surgical methods involving the eye (e.g., retinal tear or detachment surgery, macular hole surgery) as well as the instruments or devices used during such surgical procedures to determine the physiological state of the tissue within the eye, such as the retina.
The execution of microsurgical procedures, such as those involving the eye, is primarily driven by visual information available to the surgeon during the surgical procedure. For example, to aid in viewing the interior structures and regions of the eye when performing intraocular surgery, such as for example a retinal tear or detachment surgery and macular hole surgery, one or more surgical contact lenses are fitted into a lens ring that is sutured in place and spans the cornea. A cushion of transparent Healon or similar material is typically applied to the anterior surface of the eye to prevent corneal abrasion and to enhance optical clarity. In addition, a light source is introduced into the intra-ocular volume of the eye. The surgeon looks through the surgical contact lens and through the lens of the eye lens to observe the interior of the eye lighted by the light source.
Visual queues such as structure, color and the way the tissue responds to manipulation by a surgical instrument are used by the surgeon to determine anatomical structure and to make assumptions about the corresponding physiological state of the surrounding tissue. Based on these observations and assumptions, the surgeon develops a mental plan of a desired surgical approach. The surgeon then executes that plan manually. Unfortunately, in many microsurgical environments the visualization provided by existing optical microscopes is limited due to obstructed views or optical limitations.
Additionally, following execution of the plan, the surgeon typically evaluates the results or outcomes of the surgical procedure by means of such visual observations to determine if the procedure appears to be successful. Following eye surgery, the ophthalmic surgeon performs one or more diagnostics tests to determine the effectiveness of the surgical procedure. In a number of cases, however, the diagnostics test(s) performed show that the surgery was not as effective as indicated by the visual queues. Consequently, the patient again can be scheduled for surgery, whereupon the process is repeated. As a result, the patient experiences further risk for the additional surgery, experiences added discomfort because of the additional procedure(s) and increases the risk that the corrective action may be less than hoped for. Moreover, the added surgery results in increased cost to the patient or insurance carrier because of the additional corrective surgery.
There also are micro-surgical procedures such as those for example involving the middle ear, where the surgical site must be opened up or externalized in order for the surgeon to effectively visualize the surgical site. For example, in micro-surgical procedures involving the the middle ear, the middle ear is externalized (i.e., opened up) for the surgeon to observe the area.
There is disclosed in U.S. Pat. No. 5,152,295 an intra-operative diagnostic imaging device. This imaging device is in the form of a finger mounted probe and is disposed on a finger of the technician/doctor when imaging. Consequently, the use of this imaging device is limited to those situations in which the finger and finger mounted probe can access the area of interest. Such an imaging device, however, because of its physical size and arrangement cannot be used in the intraocular space of an eye.
There are ultrasonic imaging devices for ophthalmologic uses, however, such devices are external probes that are placed on an outside surface of the eye such as on the conjunctiva 4 (FIG. 1). In order for such external probes to view the retina, the ultrasonic sound must penetrate through several tissue layers (e.g., the cornea and the lens) and through approximately one inch of fluid in the intraocular space. Thus, a low frequency ultrasound wave (for example, on the order of 2 mHz) is used to image the retina. A low frequency must be used because higher frequencies are not capable of penetrating through to the retina. A low frequency ultrasonic signal, however, returns a low resolution image, whereas high frequency ultrasonic sound is capable of returning a high resolution image. Thus, fine detail of the retina is not available when using low frequency ultrasonic sound.
It thus would be desirable to provide a new imaging device and methods for performing micro-surgery that would allow the surgeon to intra-operatively image the surgical site and selected areas about the site. It would be particularly desirable to provide such an imaging device and such methods using an improved ultrasonic imaging technique that would provide intra-operative images of a higher quality in comparison to the images obtained with prior art ultrasonic imaging devices. It also would be desirable to provide such a device and methods that are particularly suited for providing high quality images of the anatomical structure of the eye such as the retina during the conduct of a surgical procedure as compared to the images using prior art ultrasonic devices. Such imaging devices preferably would be simple in construction and such methods would not require highly skilled users to utilize the device.
The present invention features a device that provides a mechanism for imaging structure and/or tissue of a surgical site during and after performing a microsurgical procedure such as ophthalmic surgical procedures. Such an intra-operative imaging device also allows a high frequency ultrasonic imaging mechanism to be disposed in close proximity to the area to be scanned/imaged (e.g., surgical site) so a surgeon is provided with high quality/high resolution images. The high quality/high resolution images provide a source of information to the surgeon that can be used to adjust the planned surgical approach so as to accommodate for any conditions not accounted for in the initial planning of the surgical approach to be taken.
An exemplary embodiment of the intra-operative imaging device includes a probe member having a predetermined length and an ultrasonic signal transmitting and receiving mechanism secured to the probe member. The predetermined length is established such that the ultrasonic signal transmitting and receiving mechanism is positioned in close proximity to the particular area or region to be scanned and disposed with a cavity of the body. In specific embodiments, the ultrasonic signal transmitting and receiving mechanism is an ultrasonic transducer, more particularly a high frequency ultrasonic transducer. The frequency of the ultrasonic signals is general established so the scanned image provides a desired amount of detail, particularly, as compared to the detail available when using prior art techniques, for the surgeon to evaluate the effectiveness of the procedure being performed and to make any adjustments to the procedure.
An imaging methodology according to the present invention includes steps of positioning an ultrasonic signal transmitting and receiving apparatus in proximity to a region to be scanned and performing an ultrasound scanning process using the ultrasonic signal transmitting and receiving mechanism during an in-process stage of a microsurgical procedure. Such a methodology includes providing an intra-operative imaging device of the present invention and inserting the probe member into a member of body such that the ultrasonic signal transmitting and receiving mechanism is proximal the region to be scanned for imaging. The method further includes evaluating the results of the scanning process performed and adjusting the surgical procedure/approach when such evaluating determines that adjustment should be performed.
Also featured are micro-surgical procedures including surgical methods involving the eye, for example, retinal tear or detachment surgery and macular hole surgery. Further featured are device kits that comprise such intra-operative microsurgical devices alone or in conjunction with other microsurgical instruments such as entry alignment devices.
Other aspects and embodiments of the invention are discussed below.